Evidence in support of highly myopic retrospective voting

Question

I am reading Democracy for Realists: Why Elections Do Not Produce Responsive Government. In Chapter 6 and 7, evidence is shown that "voters' retrospective assessments of the economy are quite myopic." For example, Chapter 7 looks at the landslide victory of Roosevelt in 1936 as a sort of case study, and shows (p191, emphasis mine):

Even in the remarkable circumstances prevailing in 1936, voters were focused on concrete economic conditions that they could see and feel when they went to the polls. Specifically, they were focused on income gains or losses over the course of the election year. Income growth earlier in Roosevelt's term, which contributed as much or more to their economic well-being, had no apparent electoral effect. That was water under the bridge. Roosevelt's reelection in 1936—and the New Deal realignment—depended crucially on a positive balance of answers to the question, "What have you done for us lately?"

They present a statistical analysis in support of this view, but I do not fully understand the presented data (likely due to my lack of knowledge about statistics).

Table 7.1 (p187), or similar results which are presented in Table 1 of Achen & Bartels (2004), uses "ordinary least squares regression parameter estimates" to indicate that "[in] every case, whereas election-year [1936] income growth has a strong positive effect on Roosevelt’s vote, previous income growth [1933-1935] has little or no effect."

It is my understanding (possibly wrong and the root of my confusion), that for them to be able to perform these statistics they would need to poll for the popular vote in the intermediate years between elections. If this were true, and with the explanation of myopic voting in mind, would you then not expect the popular vote to be higher due to recent income growth (at the time of the poll), similar to as is shown for 1936? Or, does 'myopic voting' for some reason only apply to election years?

_{Achen, C. H., & Bartels, L. M. (2004). Musical Chairs: Pocketbook Voting and the Limits of Democratic Accountability. Presented at the Annual Meeting of the American Political Science Association.}

Answer 1

The Hypothesis - No Need to Measure Off-Year Electoral Support

They do not attempt to measure electoral support in any year except 1936. Forgetting the statistics for a moment, they are using Roosevelt's 1936 re-election as a case study. They would like to explain why the percentage of people voting for Roosevelt in 1936 increased or decreased in certain states.

Their suggested explanation for these changes is that in areas where income rose in 1936 people voted for Roosevelt. Given this hypothesis there is no need to measure electoral support in off years.

However, they are concerned with showing that income growth in other years is less influential on voting in 1936. This is the core of the "myopic" part of "myopic voting". Other theories had suggested that voters were more rational and would consider their income growth across a politician's entire term. Bartels (et al.) are disputing this.

In order to accomplish this they need to measure income growth in 1933-1936. These are the potential causes they are evaluating. In their hypothesis (and their model) income growth in each year is compared to the 1936 election.

Here's a diagram showing this: